Serum pentraxin-3 in diagnosing acute appendicitis in patients with acute abdominal pain: A systematic review and meta-analysis of diagnostic test accuracy.

Background: Acute appendicitis is one of many common reasons for acute abdominal pain, and its exact diagnosis is still debatable amongst clinicians. This systematic review and meta-analysis of diagnostic test accuracy aim to look at serum pentraxin-3 performance in diagnosing acute appendicitis in patients with acute abdominal pain.

Methods: This systematic review is registered on the International Prospective Register of Systematic Reviews (CRD42022338296). The primary outcome of this study is to examine the sensitivity, specificity, and post-test probability of serum pentraxin-3 (the index test) in patients with acute appendicitis. We searched various academic databases such as Pubmed, MEDLINE, Cochrane Library, Science Direct, Google Scholar, ScieLO, MedRxiv, BioRxiv, and Research Square. Two independent authors reviewed, selected the articles, and extracted the data. The analysis was done using STATA software using the "midas" and "metandi" commands.

Results: Five articles fulfilled our inclusion criteria with 520 patients, and 27.5% of them were children. The combined sensitivity is 90.3% (95% confidence interval 78.6-95.9), and the combined specificity is 91.2% (95% confidence interval 22.1-99.7). The area under the curve is 0.94 (95% confidence interval 0.92-0.96). Fagan's Nomogram showed that the positive likelihood ratio is 10.38 (95% confidence interval 0.38-284.76) with an 87% post-test probability, while the negative likelihood ratio is 0.11 (95% confidence interval 0.04-0.27) with a 7% post-test probability. The combined negative predictive value is 0.89 (95% confidence interval 0.81-0.98), and the positive predictive value is 0.90 (95% confidence interval 0.81-0.98).

Conclusion: Serum pentraxin-3 could only be used as a confirmation test for acute appendicitis but not exclude it.